how to wires amps together?

OK I been running a 15" solo baric L7 for about a month in a nice big ported box, sounded pretty good but I wanted to give 2 12" solo baric L7's a go I am a little dissapointed as the 15" deffinately hit harder but the 12"s are a little cleaner sounding.  I ran both setups from a kicker sx 1250.1 amp so now I am thinking of buying 2 more 12's so I will have 4 all together and getting another of the same amp.

Where I am confused is, if I wired all 4 speakers together they would not be a 1ohm load anymore so i'm guessing I would leave the 2 now the way they are at there 1ohm load going to amp 1 then when I get the 2 other speakers wire them the same way but to amp2?  If this is correct how do I get the amps to work together, basicly share rca's i'm assuming?

Thanks for any help

does that amp have a line out ??

I think it does

power and ground I have a distribution block back ther already with 0 gauge going to it, remote wire, im not sure about it though

Whew - for a sec there I thought BT was recommending a cap...

What is that thing?  By the sound of the description it would boost voltage to longer cable runs?  Is that what it does?

If no pre-outs on amp 1 just use a splitter off the first amp's RCA's.